A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

Homicide squad to join missing woman case

Homicide detectives have been asked to join the investigation into the disappearance of NSW woman Allecha Boyd, with hopes fading of finding the 27-year-old alive.

Police spent Wednesday combing Lester State forest outside Coolamon, in the state's Riverina, where Ms Boyd was last seen on August 10.

A number of items found in the bushland search have been sent for forensic examination, although detectives stress the items are not "significant" at this stage.

Since her disappearance, Ms Boyd, who was living in Wagga Wagga, has not contacted her family, accessed her bank accounts or posted to social media.

Police have said they have "serious concerns for her welfare".

"Given the circumstances of this case and that regular contact has ceased and that she hasn't been seen or heard of since the 10th, on that basis alone there's enough concern regarding her welfare to warrant specialist police involvement," Detective Inspector Darren Cloake told AAP on Thursday.

Police are hoping to bring Ms Boyd's family to Wagga in coming days to make another public appeal for information.